The present invention relates to a management technology for presence that is the dynamic attribute of users of information processing devices in a system composed of a plurality of information processing devices connected to a network.
Highly portable information terminals, such as cellular phones and PDAs (Personal Digital Assistant) that have a function to connect to the Internet and a function to send and receive electronic mails and instant messages, are popular today. On the other hand, the location of an end user with a user terminal can be identified and the resulting information on the location can be stored in a server via the Internet using the wireless communication technology and the GPS (Global Positioning System) technology.
A service is now being devised that uses such a user terminal and a location management technology to directly deliver information to the user terminals of end users via an electronic mail or an instant message. The information that is delivered includes news about an area where user is now positioned and advertisements for the products and services provided by the stores in that area.
Examples of technology that realizes such a service include an information delivery system and a user terminal described in U.S. Pat. No. 5,740,369. This publication discloses an information delivery system in which the reader of an automatic ticket gate installed at a station reads the service contract data of an end user from the portable storage medium carried by the end user, the service contract data are sent to an information management device, the information management device selects information according to the contract data, and a transmission management device delivers the selected information to the user terminal of the end user.
The information delivery system and the user terminal described above allow an information provider to designate a condition for a location, which is the dynamic attribute of end users, and deliver information only to end users who match the condition. For example, the information provider can send information on the stores near the Tokyo station only to the end users who are near the Tokyo station. As a result, as compared with information delivery based on static attributes such as age and sex, timely information can be delivered.